The present invention relates to a stator coil lacing machine for lacing the stator end turns of an electrodynamic machine. More particularly, the present invention relates to a stator coil lacing machine having improved cord handling capabilities and lacing cord handling components that can be adjusted without disassembly of the machine so that the machine accommodates a range of stator stack heights.
Electrodynamic machines include such things as induction motors. These motors typically include a stator and a rotor. The stator may include a metallic core with a plurality of coils or windings running through the core. An alternating current may be passed through these coils to generate an alternating magnetic flux field. The rotor may have a plurality of coils or windings in which an alternating current is induced by the alternating magnetic flux field of the stator. The end coils or end turns of the stator are grouped together at axial ends of the stator and are often laced or stitched together to prevent their interfering with other components of a device. The end turns are often coated with an epoxy or resin subsequent to stitching. This coating helps reduce movement of the wires and provides an insulative barrier between the wires and other objects. Lacing in this case helps assure that the coils are tightly grouped together prior to coating.
Lacing machines for lacing stator coils are known. Use of a stator coil lacing machine avoids many of the manual operations otherwise necessary for lacing or stitching stator end coils and thus often reduces labor costs and increases productivity and quality.
Stators come in a variety of sizes depending on the particular application in which the stator is used. Stator coil lacing machines are accordingly often constructed to accommodate a range of different stator sizes. However, with some of these machines, it is necessary for the operator to disassemble various parts of the machine in order to adjust one or more of the lacing cord handling components thereof so as to accommodate a particular stator size. The necessity for such manual disassembly adds labor costs and increases production time.
Some stator coil lacing machines have one or more pneumatically or fluidly actuated clamps located inside the arbor of the machine on which the stator is oriented during lacing of the end turns thereof. Machines with such clamps often result in arbors having large longitudinal lengths in order to accommodate the stroke of the one or more pneumatically or fluidly actuated clamps. The larger the longitudinal length of the arbor, the more effort is required to place the stator on and remove the stator from the arbor.
Some stator coil lacing machines utilize clamps that are externally mounted relative to arbors of the machines. These clamps are used to pull lacing cord stitched around end turns of a stator upon completion of the lacing thereof in order to set any knots formed to secure the stitching. These external clamps often generate excess pieces of lacing cord that must be cut and vacuumed away prior to removal of a stator from a machine. This results in waste of lacing cord and the need for extra components for a machine.
Another characteristic of some stator coil lacing machines is that the leads of the stator must be manually held and moved during lacing of the coils of the stator. The leads must be held and moved in order to prevent them from coming into contact with the one or more lacing needles of the stator coil lacing machine. Thus, one or both of the hands of the operator of a stator coil lacing machine is/are preoccupied during lacing of the coils of the stator. This has the disadvantage of preventing the operator from performing other tasks during stator coil lacing and thus lowers his or her productivity. In addition, a potential safety hazard exists in that fingers or hands of an inadvertent or careless operator may come in contact with moving components of the stator coil lacing machine such as the lacing needles.
A stator coil lacing machine having lacing cord handling components that can be adjusted without disassembly of the machine so as to accommodate a range of stator sizes, would be a welcome improvement. Also, reduction in the longitudinal length of the arbor would allow an operator to more easily place a stator on and remove a stator from the arbor. Such reduction could be achieved by eliminating the use of hydraulic or fluidly actuated clamps inside the arbor. In addition, elimination of excess lacing cord that needs to be cut and vacuumed away because of the use of external clamps would be a welcome improvement. Such improvement would conserve on lacing cord and reduce machine components. Finally, a stator coil lacing machine that releasably secures the leads of the stator during lacing of the coils thereof so as to prevent the leads from coming into contact with the lacing needles would also be a welcome improvement.
Accordingly, the present invention includes a stator coil lacing machine having structure for orienting a stator on the stator coil lacing machine so that the stator coils thereof can be laced. The orienting means includes an arbor on which the stator is placed. The stator coil lacing machine also includes structure for stitching lacing cord around the stator coils and cord handling structure for receiving a continuous length of cord and delivering the cord to the stitching structure. The cord handling structure is disposed entirely within the arbor. The stator coil lacing machine of the present invention has adjusting structure that allows for the adjustment of the relative positioning of the stitching structure and cord handling structure without disassembly of the machine so that the machine accommodates a range of stator stack heights.
The stitching structure may include a needle. The adjusting structure may include a rail that is substantially perpendicular to the needle, a needle housing in which the needle is disposed, a clamp that surrounds a peripheral portion of the rail, a portion of the clamp being attached to the needle housing, and at least one screw that threadingly engages the clamp to releasably secure the clamp around the peripheral portion of the rail along at least a portion of the longitudinal length of the rail.
The cord handling structure may include a cord feeder tube having lacing cord disposed therein and at least one cord pin attached to the feeder tube for directing lacing cord toward the stitching structure. The adjusting structure may include a clamp collar and at least one screw that releasably secures the clamp collar to the cord feeder tube and the cord pin. In one embodiment, the clamp collar and cord pin may surround a peripheral portion of the cord feeder tube and have two screws threadingly engaging the clamp collar and cord pin to releasably secure the cord pin and clamp collar around a periphery portion of the cord feeder tube along at least a portion of a longitudinal length of the cord feeder tube.
The cord handling structure may also include a clamp for securing the cord. The adjusting structure may include a screw that threadingly engages the clamp and releasably secures the clamp along a longitudinal length of the arbor.
Structure may be provided for holding the leads of the stator during stator coil lacing so that the leads do not come in contact with the stitching structure. The holding structure may include a lead retainer. The lead retainer may include a block having at least one groove formed therein for receiving and securing the stator leads and a hinge that allows the block to pivotally move with respect to the stator.
The stator coil lacing machine may further include cutting structure for cutting the lacing cord upon completion of the lacing of the stator coils of the stator. The adjusting structure may adjust the positioning of the cutting structure relative to the positioning of the handling structure so as to accommodate a range of stator stack heights. The cutting structure may include a cutting mechanism having a single heated wire for melting through the cord delivered by the handling structure. The adjusting structure may include a rail, a clamp attached to the cutting structure and surrounding a peripheral portion of the rail, and at least one screw that threadingly engages the clamp to releasably secure the clamp around the peripheral portion of the rail along at least a portion of the longitudinal length of the rail.
In a preferred embodiment, the stator coil lacing machine includes an inner arbor having an adjusting slot and an opening. The adjusting slot and opening extend along a part of a longitudinal length of separate portions of the periphery of the inner arbor. The stator coil lacing machine further includes an outer arbor within which a portion of the inner arbor is disposed so that the outer arbor surrounds the periphery of the inner arbor. The outer arbor has an access slot along at least a part of a longitudinal length of a periphery of the outer arbor. The access slot is disposed adjacent the adjusting slot of the inner arbor. The outer arbor further has an opening defined therein along at least a part of a longitudinal length of a different portion of the periphery of the outer arbor than that portion of the periphery in which the access slot is defined. The opening of the outer arbor is disposed adjacent the opening of the inner arbor. A cord feeder tube is disposed in the inner arbor for supplying lacing cord. Upper and lower lacing needles are provided for stitching lacing cord around the stator coils. Upper and lower cord pins are attached to the cord feeder tube and disposed in the openings of the inner and outer arbors so that the upper and lower cord pins direct lacing cord towards the upper and lower needles, respectively. First adjusting structure is provided for adjusting the position of the upper cord pin along at least a portion of a longitudinal length of the cord feeder tube. The first adjusting structure is accessible via the openings in the inner and outer arbors. Second adjusting structure is provided for adjusting the positioning of the upper lacing needle. An upper clamp is mounted within the inner and outer arbors and has a portion disposed in the openings of the inner and outer arbors. The upper clamp is drivingly engaged by the inner arbor. Third adjusting structure is provided for adjusting the position of the upper clamp along the adjusting slot of the inner arbor. The third adjusting structure is accessible via the access slot in the outer arbor. A lower clamp is drivingly attached to the inner arbor and disposed in the openings of the inner and outer arbors.
The first adjusting structure may include a clamp collar and at least one screw that releasably secures the clamp collar to the cord feeder tube and the upper cord pin. The clamp collar and a bar portion of the upper cord pin may surround a peripheral portion of the cord feeder tube and have two screws threadingly engaging the bar portion and the clamp collar to releasably secure the bar portion and the clamp collar around the peripheral portion of the cord feeder tube.
The second adjusting structure may include a rail that is substantially perpendicular to the upper lacing needle, a needle housing in which the upper lacing needle is disposed, a clamp that surrounds a peripheral portion of the rail, a portion of the clamp being attached to the needle housing, and at least one screw that threadingly engages the clamp to releasably secure the clamp around a peripheral portion of the rail along at least a portion of the longitudinal length of the rail.
The peripheral portions of the upper and lower clamps may engage the lacing cord supplied by the respective upper and lower cord pins during certain portions of the lacing of the stators such that the lacing cord directed by the upper and lower cord pins is fixedly secured against movement between the peripheral portions of the upper and lower clamps and peripheral portions of the outer arbor that define the opening therein.
The third adjusting structure may include a screw disposed in the adjusting slot of the inner arbor that threadingly engages the upper clamp and releasably secures the upper clamp along the adjusting slot of the inner arbor. The upper clamp may include a ring clamp that is disposed around a periphery portion of the cord feeder tube, a generally L-shaped clamp attached to the ring clamp, a portion of the L-shaped clamp being disposed in the openings of the inner and outer arbors, and a key attached to the ring clamp and disposed in the adjusting slot of the inner arbor such that the upper clamp is drivingly engaged by the inner arbor.
The first, second and third adjusting structures may adjust the relative positioning of the respective upper cord pin, upper needle, and upper clamp so as to accommodate a range of stator stack heights.
The stator coil lacing machine of the preferred embodiment may further include structure for holding the leads of the stator during stator coil lacing such that the leads do not come in contact with the upper and lower lacing needles during lacing. The holding structure may include a lead retainer.
The stator coil lacing machine of the preferred embodiment may also include structure for cutting the lacing cord directed by the upper and lower cord pins upon completion of the lacing of the stator coils of the stator. The cutting structure may include an upper cutting mechanism having a single heated wire for melting through the cord of the upper cord pin and a lower cutting mechanism having a single heated wire for melting through the cord of the lower cord pin. The positioning of the upper cutting mechanism may be adjustable relative to the positioning of the upper cord pin so as to accommodate a range of stator stack heights.
The present invention provides a method of adjusting a stator coil lacing machine without disassembly of the machine to accommodate a range of stator stack heights. The adjustment method includes the steps of orienting a stator on an arbor of the stator coil lacing machine so that the coils thereof can be laced, the stator having a particular stack height. Adjusting structure disposed within the arbor for delivering cord to be laced around the stator coils, the adjustment being made so as to accommodate the particular stack height of the stator. Adjusting structure for stitching the cord around the stator coils, the adjustment being made so as to accommodate the particular stack height of the stator and position the stitching structure relative to the delivering structure. Adjusting structure disposed within the arbor for securing the cord, the adjustment being made so as to accommodate the particular stack height of the stator and position the securing structure relative to the delivering structure and stitching structure. The delivering structure, stitching structure, and securing structure are all adjustable without disassembly of the stator coil lacing machine.
The above method may allow the delivering structure, stitching structure, and securing structure to be adjusted via loosening and subsequent tightening of screws that can be accessed without disassembly of the stator coil lacing machine. The stator coil lacing machine may further include the step of adjusting structure for cutting through the cord of the delivering structure upon completion of the lacing of the stator coils of the stator. This adjustment is made so as to accommodate the particular stator stack height of the stator and position the cutting structure relative to the delivering structure, stitching structure, and securing structure.
The stator coil lacing machine may have both upper and lower delivering structure, upper and lower stitching structure, and upper and lower securing structure. If such is the case, only the upper delivering structure, upper stitching structure, and upper securing structure need be adjusted so as to accommodate the particular stack height of the stator. The above method may further include the step of adjusting the upper structure for cutting lacing cord upon completion of the lacing of the stator coils of the stator. This adjustment is made so as to accommodate the particular stack height of the stator and position the upper cutting structure relative to the upper delivering structure, upper stitching structure, and upper securing structure.
The above method may further include the step of positioning a lead retainer around leads of a stator during lacing of the stator coils of the stator.